Weapon mount and vehicle, vessel or aircraft comprising a gun carriage with such a weapon mount

Abstract

A weapon mount (9) comprising a base (10), mounting means (12) connected thereto for holding a gun (13), a pivot mechanism (16) placed between the base and the mounting means, thereby allowing a pivoting motion about a first axis (17) and an actuator (19) configured to pivot the mounting means. The weapon mount further comprises a sensor (40) configured to sense an angular position or rotation of the base around the first axis with respect to an external reference, control means (42) connected to the sensor and to the actuator, and a user interface (25) connected to the control means for switching between a first and a second operational mode of the weapon mount. In the first operational mode the actuator is inactive, in the second operational mode the control means drive the actuator to compensate for a rotation of the base. Furthermore, a platform with such a weapon mount thereon.

Description

[0001] WEAPON MOUNT AND VEHICLE, VESSEL OR AIRCRAFT COMPRISING A GUN CARRIAGE WITH SUCH A WEAPON MOUNT

[0002] The invention relates to a weapon mount for use on a vehicle, vessel or aircraft, the weapon mount comprising a traversing base which can be rotatably fixed to a gun carriage on the vehicle, vessel or aircraft so as to allow traversing of the base, mounting means connected to the base, wherein the mounting means are configured to hold a gun in a mounted position, the mounting means having an elevation corresponding to an elevation of the gun in the mounted position, a pivot mechanism placed between the base and the mounting means, the pivot mechanism allowing a pivoting motion about a first axis of the mounting means with respect to the base, so that the elevation of the mounting means can be changed, and an actuator configured to pivot the mounting means about the first axis with respect to the base in accordance with a command signal.

[0003] From US 2007 / 0144338 Al a weapon is known which has an eccentrically-pivoted barrel on a movable base. A drive mechanism acts between the barrel and the base to permit and enable the elevation of the barrel relative to the base to be selectively changed. A compensation device acts between the barrel and base to compensate for the unbalance of the barrel. The compensation device includes a gyroscope mounted on the barrel and arranged to provide an output signal, a set point generator, a closed-loop control device and an actuating element. The actual position of the barrel is sensed by the gyroscope, which supplies its output signal to the set point generator. The set point generator produces a set force value as a function of the gyroscope output signal. The set force value is supplied to the closed-loop control device, which produces a set point value that is, in turn, supplied to the actuator for controllably changing the elevation of the barrel.

[0004] The weapon as disclosed in US 2007 / 0144228 Al has an imbalance due to it being eccentrically- pivoted. The imbalance is compensated for by using the compensation device, which has a gyroscope mounted on the barrel. To some extent, the compensation device may be used to balance for movement of the base. However, said device can not adequately compensate movements of the base which would occur on a vehicle, vessel or aircraft. When mounted on a vehicle, vessel or aircraft, a weapon is subject to movements of the vehicle, vessel or aircraft, causing changes in orientation of the weapon. As an example, reference is made to figures 1A and IB and the corresponding description below. The movements of the vehicle, vessel or aircraft may complicate aiming of the weapon. As such, a need exists for a weapon mount which aids in aiming. This need exists all vessels, vehicles and aircraft, as movement of these platforms causes a similar decrease in accuracy. An atempt to meet this need was made in US 9,074,847 Bl, but leaves room for improvement. US 9,074,847 Bl explains in detail in column 4, lines 4 - 31 the operation of a proposed stabilized platform. The platform is placed on a host platform, such as a patrol boat. Stabilization is based on a detection and calculation of the motion of the host platform (cf. col. 4, lines 14 - 16), which together with an aiming vector (defining the desired aim) leads to the calculation of a correction vector. The correction vector is thus the difference between the desired aim and the host platform movement. Uines 22 - 26 continue to state that the difference between aiming orientation and the desired aiming orientation can be corrected for using correction commands derived from the correction vector, i.e. correction is based on the sensed or detected movement of the host platform.

[0005] The system of US 9,074,847 Bl is thus effective in preserving the desired aim, as long as host platform movement is the only movement to be compensated for. The applicant has found however that a weapon mount with a rotatable base, that allows traversing, is an improvement over the stabilized base proposed in US 9,074,847 Bl. It is noted that in strictly horizontal conditions, rotation of the base with respect to the vehicle causes no issues in the vertical i.e. elevation direction. However, when the host platform is tilted e.g. sideways, a rotation of the platform with respect to the host platform (around the upwards axis) also causes a change in vertical aim (i.e. the elevation). The system US 9,074,847 Bl cannot correct for this additional movement, as its correction is based on detected movement of the host platform. Therefore, a need remains to improve the disclosure of US 9,074,847 Bl.

[0006] The invention aims to at least partly fulfil said need, by providing a weapon mount that can aid in aiming.

[0007] The need is fulfilled at least partly by a weapon mount of the above-described type, characterized by a sensor configured to sense an angular position or rotation of the base with respect to an external reference, and to provide a sensor signal in accordance with the sensed angular position or rotation respectively; and control means, connected to the sensor for receiving the sensor signal and to the actuator to provide the command signal, and a user interface connected to the control means for providing a switching signal, wherein the control means are configured to switch between a first and a second operational mode of the weapon mount based on the switching signal, wherein in the first operational mode the actuator is inactive, and in the second operational mode the control means provide the command signal in dependence of the sensor signal so that the actuator pivots the mounting means around the first axis with respect to the base so as to compensate for changes in the elevation of the mounting means caused by traversing the base when it is tilted. Since in the first operational mode the actuator is inactive, a user (such as a soldier) may change an elevation of the gun by pivoting it with respect to the base. As such, the soldier can take aim at a target in the first operational mode. As such, the actuator being inactive may be defined as the operator not actively controlling the rotation of the mounting means with respect to the base around the first axis.

[0008] When the soldier is satisfied with the aim, he or she can use the user interface to switch to the second operational mode, in which the actuator compensates for a rotation of the base around the first axis. As such, if after entering the second operational mode the vehicle, vessel or aircraft on which the weapon mount is used moves, thereby changing the orientation of the gun around the first axis, and thereby the elevation of the gun, the aim the user took may be maintained or may be maintained more closely. This may increase the perceived threat of the weapon.

[0009] The sensor may be arranged on the base. Accordingly a movement of the base may be sensed directly and accurately, so that the actuator can be driven in accordance. In comparison to the weapon of US 2007 / 0144338 Al this may be more advantageous, as the gyroscope of said document is arranged on the barrel and may thus also pick up on movements of the barrel with respect to the base, for instance caused by the soldier. Arranging the gyroscope on the barrel thus introduces inaccuracies in sensing the movements of the base, which ultimately prevents the system from compensating for movements of the vehicle, vessel or aircraft.

[0010] The sensor may also be arranged on the mounting means or on the gun. As a rotation of the mounting means includes a rotation of the base, the sensor can also sense a rotation of the base when it is arranged on the mounting means or the gun.

[0011] In particular, the control means may be configured to, in the second operational mode, compensate for the rotation of the base around the first axis in order to keep the elevation of the mounting means, and thus of the gun, substantially constant.

[0012] Since the sensor is configured to sense an angular position or rotation of the base with respect to an external reference, the sensor registers movement of the vehicle to which the base is attached on the one hand, and also the change in elevation stemming from a traversing motion of the base, i.e. of a rotation of the base with respect to the vehicle. The sensor thus senses the combination of the vehicle movement and user applied rotation, also called sweep or traversal. Accordingly, it becomes possible to keep the elevation of the mounting means (defined equal to the elevation of the weapon mounted to the mounting means) constant, even if the weapon is traversed by rotating the base with respect to the gun carriage, and even when the gun carriage is tilted (e.g. sideways) due to movement of the vehicle.

[0013] The invention thus in part stems from the realization that when a user is allowed to traverse the weapon, the orientation of the vehicle is no longer sufficient for predicting the change in elevation imparted on the base, mounting means and weapon.

[0014] This can be best understood by supposing on the one hand an upright gun carriage. In this case, traversal of the base (i.e. rotation with respect to the gun carriage) causes the weapon to sweep, thereby describing a horizontal path from left to right or vice versa. The rotation for this sweeping motion takes place about an upwards axis, which is vertical if the gun carriage is upright. If on the other hand the gun carriage is titled sideways, the upwards axis is no longer exactly vertical. The same rotation of the base with respect to the gun carriage about that upwards axis therefore also has a vertical component. The sweep of the weapon therefore goes from top left to bottom right, vice versa, or top right to bottom left, or vice versa depending on the direction of the tilt of the gun carriage.

[0015] In order to keep the elevation of the weapon stable, the elevation of the mounting means must be kept stable (after all, the elevations are equal). The elevation of the mounting means can be kept stable by sensing the combination of the vehicle motion and the base motion, which corresponds to the orientation of the base with respect to an external reference. The orientation can be registered in three mutually perpendicular axes, for instance two horizontal axes and a vertical axis. Typically, axes are chosen that correspond to axes of the weapon in a neutral position. Nevertheless, the orientation of the base may also be sensed in any other system of axes, for instance one local to the weapon and / or mounting means and / or base, as long as reference to the external environment exists. Of course instead of orientation a change in orientation, called rotation, can be sensed and integrated if needed.

[0016] It is noted that although in this application it is described that a user aims to hit a target, the user’s objective may not always be to hit e.g. an enemy. For instance, by aiming close to an enemy, a soldier may prevent the enemy from coming closer merely by providing a perceived threat and without risking casualties. Nevertheless, accuracy remains important. In particular, if the soldier is not able to shoot with sufficient accuracy, the perceived threat is smaller or absent, and the enemy may be able to come closer. In this example, the target may be said to be close to, but not on, the enemy. As such, the above-described advantage of compensating for movements of a vehicle, vessel or aircraft is relevant even if a user wants to shoot close to, but not hit, a target. The perceived threat is increased using the weapon mount as described herein, following an increase of the time-on-target. The time-on-target is a parameter which reflects the total time during which the aim of the weapon is accurate. On a moving vehicle, the time-on-target is reduced due to movements of the vehicle. Since the target can only be hit during the time-on-target, a reduced time-on-target offers a smaller window for firing, so that the perceived threat of the weapon is diminished. By applying the weapon mount as described herein, the time-on-target is increased with respect to an uncompensated situation on a moving vehicle, and may be approximately equal to a typical time-on-target on a non-moving vehicle or the ground.

[0017] The increase in accuracy achieved using the weapon mount described herein may also be seen following from the spread of a series of shots fired while a vehicle is moving with the weapon mount activated, compared to a test in which the weapon mount was not activated, and a control test in which the vehicle was not moving. The weapon mount as described herein may allow sufficient compensation to obtain a spread similar to that of the control test, allowing the conclusion that motion of the vehicle is compensated for. The remaining spread in the control test and the active test follows from e.g. inaccuracies in the weapon, the ammunition, the shooter and external influences.

[0018] It is noted the gun carriage to which the base can be fixed may be movably mounted on the vehicle, vessel or aircraft. In particular, the gun carriage may be arranged on e.g. a looped rail. The gun carriage may however also be fixed with respect to the vehicle, vessel, or aircraft. Accordingly, the gun carriage can be a stand.

[0019] The mounting means may define a unique position of a gun with respect to the mounting means, which may be referred to as the mounted position. As such, the mounting means can be described as having directional definitions normally associated only with the gun. In particular, the mounting means may define an elevation, and a direction of fire, and for instance a top and bottom, and an upright position. Throughout this application, directional definitions of the mounting means and / or the weapon mount are therefore inferred from the gun if it were mounted on the mounting means unless stated otherwise.

[0020] In normal use, the first axis is at a right angle with respect to a direction of fire. Moreover, the first axis is kept generally parallel to the horizon. This achieved by keeping the weapon mount substantially upright. As such, the direction of the first axis can be easily inferred from the weapon mount. Of course when the weapon mount is tilted e.g. sideways (about the axis defined by the direction of fire), it is no longer parallel to the horizon, which cause the aforementioned change in elevation when traversing.

[0021] The sensor may sense the rotation of the base by sensing the corresponding angular position more than once, and by then calculating the rotation.

[0022] When the actuator is inactive, the actuator may allow the mounting means to rotate freely around first axis with respect to the base.

[0023] This can be achieved in multiple ways. As a first, and preferred way, the actuator may provide a for instance relatively small mechanical resistance when it is inactive, so that a user can pivot the mounting means by using manual force. As a second way, a force sensor may be provided to sense manual force exerted by a user, which sensed force may then be used to control the actuator to move in the direction corresponding to the exerted force.

[0024] The weapon mount may further comprise an on / off-switch, on or separate from the user interface. It is noted that in the first operational mode, in which the actuator is inactive, the weapon mount may be switched on, as well as in the second operational mode.

[0025] It is noted that an advantage with respect to the prior art may be achieved with a weapon mount according to the preamble, comprising the sensor and the control means, wherein the control means are configured to provide the command signal in dependence of the sensor signal so that the actuator pivots the mounting means around the first axis with respect to the base so as to compensate for changes in the elevation of the mounting means caused by traversing the base when it is tilted.

[0026] As such, it is not strictly necessary to provide the user interface and to allow switching between the first and second operational mode.

[0027] In an embodiment of the weapon mount, the sensor is further configured to sense an angular position and / or rotation of the base about the first axis and a second and a third axis, both being substantially perpendicular to each other to and the first axis, and wherein the control means are configured to, in at least the second operational mode:

[0028] - calculate or look up a predicted change in elevation of the mounting means based on the sensed angular positions and / or rotations; and - provide the command signal to compensate for the predicted change in elevation of the mounting means, the actuator thereby keeping the elevation of the mounting means substantially constant.

[0029] The weapon mount according to this embodiment may be able to compensate for a change in elevation even if the weapon mount is not perfectly upright. As an example, if the weapon mount is rotated, for instance by a few degrees, around an axis parallel to the direction of fire, a rotation of the base around the first axis with respect to the external reference, e.g. the horizon, accounts for a change in elevation that is related, but not necessarily equal, to said rotation around the first axis. After having sensed the rotation around the second axis, a predicted change in elevation can be calculated and can be compensated for accordingly.

[0030] Further, a simultaneous rotation about the axis parallel to the direction of fire and a substantially vertical axis may cause a change in elevation as well. Such a combination of rotations may for example occur when the weapon mount is not perfectly upright, and a user traverses the gun, i.e. moves the gun from left to right or vice versa. By sensing a rotation around three axes, the weapon mount can compensate for these rotations as well. In fact, by sensing the rotation around all three axes, the weapon mount may be able to keep the elevation substantially constant regardless of the movements of the vehicle, vessel or aircraft present during normal operation thereof, and regardless of a traversing motion of the gun.

[0031] A vertical movement of the vehicle, vessel or aircraft may complicate aiming. However, when targets are at a sufficiently large distance, a rotation of the vehicle, vessel or aircraft about the first axis, which thus changes the elevation of the gun, is much more detrimental to the accuracy than a displacement of the same along the vertical axis. As such, by compensating for rotation, even if not compensating for displacement, the weapon mount may increase accuracy.

[0032] As the change in elevation is defined by the sensed angular positions and / or rotations, it is possible to calculate the predicted change in elevation for a series of possible angular positions and / or rotations. Then, for a sensed angular position and / or rotation, the corresponding predicted elevation can be looked up, for instance in a database or a table. Accordingly, calculation need not be performed multiple times.

[0033] In another embodiment of the weapon mount, the control means are configured to store an angular position of the base based on the sensor signal upon switching to the second operational mode, and to provide the command signal in accordance with a comparison of the sensor signal and the stored angular position in the second operational mode. As such, the control means may be able to calculate an elevation of the gun at the moment of switching to the second operational mode, and to provide the command signal such that said elevation is maintained.

[0034] It is noted that it is possible to further sense or estimate an angular position and / or rotation of the mounting means with respect to the base around the first axis. Such an estimate may e.g. be based the command signal and predefined behavior of the actuator. The actuator may comprise an internal feedback control loop, so that a set point may be provided to the actuator via the command signal. If the feedback control loop is sufficiently effective in achieving the set point, it may not be necessary to sense the angular position and / or rotation of the mounting means around the first axis with respect to the base outside of the feedback control loop. Nevertheless, said angular position and / or rotation may be sensed by a sensor, and provided to the control means by means of a signal. The control means may then be configured to calculate the elevation using said signal.

[0035] Additionally or alternatively, the control means may be configured to predict the change in elevation based on said signal.

[0036] The sensed or estimated angular position and / or rotation of the mounting means with respect to the base around the first axis may be saved upon switching to the second operational mode, and may for example be used in keeping the elevation substantially constant.

[0037] In yet another embodiment of the weapon mount, which is particularly practical, the actuator is a linear actuator which is rotatably connected to the mounting means in order to apply a torque on the mounting means around the first axis.

[0038] The actuator may be self-aligning. The self-alignment may be achieved by coupling the actuator to at least one of the base and / or the mounting means via a pin joint and / or a ball-and-socket joint, and / or to at least one of the base and / or the mounting means via joint allowing rotational and / or translational play.

[0039] A self-aligning actuator may reduce or remove the risk of the actuator jamming due to non- alignment. As non-alignment may occur due to recoil when firing the gun, using a self-aligning actuator on the weapon mount is particularly advantageous.

[0040] In yet another embodiment of the weapon mount, the user interface is further configured to provide an adjustment signal to the control means upon receiving user input, wherein, in the second operational mode, the control means are configured to change the command signal in order to change the elevation of the mounting means based on the adjustment signal.

[0041] In this embodiment, the weapon mount allows a user to roughly set an aim, for instance by aiming before entering the second operational mode, and to consecutively fine-tune the aim using the user interface. This may be particularly useful under non-ideal conditions, where it may be difficult or impossible to set a perfect or adequate aim without fine-tuning.

[0042] For providing the adjustment signal, the user interface may comprise one or more buttons or knobs, for instance a button or knob having a neutral position and an up and down position.

[0043] In particular, the control means may be configured to incrementally change the elevation of the mounting means on the basis of the adjustment signal. This allows the user to fine-tune the aim relatively accurately.

[0044] In yet another embodiment of the weapon mount, the user interface is further configured to provide a reset signal to the control means upon receiving user input, wherein the control means are configured to change the command signal to move the mounting means to a predetermined elevation upon receiving the reset signal.

[0045] By providing a reset function for moving to a predetermined elevation, said elevation may be used as a reference. A user may thus use the reset function to easily and / or quickly move to the predetermined elevation. This embodiment may be particularly useful on for instance a navy vessel, in which case targets are normally at or near the horizon. As such, the predetermined elevation may be horizontal.

[0046] The user interface may comprise a button or knob for providing the reset signal.

[0047] In yet another embodiment of the weapon mount, the weapon mount further comprises a handle fixedly connected to the mounting means.

[0048] The handle may be used by a user to firmly grip the mounting means. The user may use his or her other hand to grip the gun. The handle may thus form a second point of contact, so that the user may easily and / or accurately change aim.

[0049] Without a handle, a user must resort to holding the gun with two hands, which removes the second point of contact and thus may make it more difficult to change aim. The use of a handle on the weapon mount may bring advantages over the prior art even without the user interface allowing to switch between the two operational modes. As such, a weapon mount having the base, the mounting means, the pivot mechanism, the actuator and the sensor, with the control means configured to provide the command signal in dependence of the sensor signal so that the actuator pivots the mounting means around the first axis with respect to the base so as to compensate for a rotation of the base around the first axis, and further including the handle, is also advantageous.

[0050] In yet another embodiment of the weapon mount, a grip part of the handle is disposed at a distance from the mounting means.

[0051] Disposing the grip part of the handle at a distance from the mounting means may make it easier for a user to exert a torque on the mounting means. The handle may extend towards a user, at least during use of the mounting means. The grip part may be disposed at e.g. a minimal distance of 20 cm from the mounting means.

[0052] In yet another embodiment of the weapon mount, the mounting means have a view axis corresponding to a view axis of a gun in the mounted position, a grip of the gun defining a grip position along the view axis, wherein the grip part is arranged at a position along the view axis corresponding to the grip position along the view axis.

[0053] In this embodiment the grip part may be arranged lateral to the grip of a gun in the mounted position. Said embodiment may be particularly comfortable for a user, and may aid the user in accurately performing a sweeping motion with the gun.

[0054] In yet another embodiment of the weapon mount, the mounting means have a vertical axis corresponding to a vertical axis of a gun in the mounted position, a grip of the gun defining a grip position along the vertical axis, wherein the grip part is arranged at a position along the vertical axis corresponding to the grip position along the vertical axis.

[0055] In this embodiment the grip part may be arranged lateral to the grip of a gun in the mounted position. Said embodiment may be particularly comfortable for a user, and may aid the user in accurately changing the elevation of the gun.

[0056] The above-described position of the grip part of the handle may additionally or alternatively be advantageous by providing a way for the user to firmly grab onto the weapon mount and the gun, thereby allowing the user to keep him- or herself upright by supporting on the weapon mount and the gun, even if the vehicle, vessel or aircraft moves.

[0057] The grip part and the grip of the gun in the mounted position may be about a shoulder-width apart.

[0058] In yet another embodiment of the weapon mount, the user interface is arranged on the handle. More specific the UI may be arranged on the grip part. This may allow operation of the user interface while holding onto the handle. As such, a user need not release the grip part or move one or both hands to operate the user interface.

[0059] In yet another embodiment of the weapon mount, the weapon mount further comprises a decoupling mechanism for decoupling the actuator from the mounting means.

[0060] The decoupling mechanism may allow a user to operate the gun free of any influence of the actuator after decoupling. Accordingly, the decoupling mechanism can be used as a failsafe, for instance for in case the actuator is jammed. The decoupling mechanism may allow for a mechanical decoupling. Moreover, decoupling the actuator may be useful to circumvent a fault in the actuator or control means prohibiting effective use of the gun. The mechanical decoupling can be effective as a failsafe in addition to an electronic deactivation, for instance in the first operational mode.

[0061] The decoupling mechanism may be realized by using a pin joint for coupling the actuator to the mounting means, wherein the pin joint comprises a pin rotationally guided by a guide, wherein the pin is removable from the guide. The pin may be re-insertable into the guide, to reverse the decoupling, i.e. to recouple the actuator to the mounting means. Thus, the decoupling mechanism may be reusable.

[0062] The decoupling mechanism may be user-operable so that decoupling can be effected without the use of any tools.

[0063] As an alternative, a decoupling mechanism may be provided to decouple the actuator from the base. Such a decoupling mechanism may be of the above-described type.

[0064] In yet another embodiment of the weapon mount, at least the actuator, the sensor and the control means are arranged towards a side of the base and / or the pivot mechanism and / or the mounting means. Such a lateral arrangement allows a relatively large elevation range for the mounting means, by leaving a space above and / or below a gun in the mounted position free.

[0065] The side of the base and / or the pivot mechanism and / or the mounting means may be defined as lateral of a gun in the mounted position. At least the actuator, the sensor and the control means may be arranged on a similar height as the base and / or the pivot mechanism and / or the mounting means, i.e. in substantially the same horizontal plane.

[0066] In particular, where the base includes a bottom on a side facing away from the pivot mechanism, at least the actuator, the sensor and the control means may be arranged further towards the mounting means than the bottom as seen in a direction from the bottom to the mounting means.

[0067] As such, at least the actuator, the sensor and the control means may be arranged higher than the base, at least during use of the weapon mount. In particular, at least the actuator, the sensor and the control means are arranged higher than the base in a neutral elevation of the mounting means. Preferably at least the actuator, the sensor and the control means are arranged higher than the base regardless of the elevation of the mounting means.

[0068] In yet another embodiment of the weapon mount, the base has a bottom defining a plane, which in use is substantially horizontal, wherein at least the mounting means, the actuator, the sensor and the control means are arranged above said plane, regardless of the elevation of the mounting means.

[0069] Said plane may define a minimum height that components of the weapon mount, such as the mounting means, the actuator, the sensor and the control means can reach. As such, a risk of these components colliding with other objects, for instance on the vehicle, vessel or aircraft, may be reduced. In yet another embodiment of the weapon mount, the user interface comprises at least one button or knob configured to trigger the switching signal. The button may be physical. Further buttons or knobs may be provided, e.g. for the adjustment signal. A separate on / off switch may be provided.

[0070] A button or knob may allow a user to locate the button or knob before desiring to operate said button or knob, so that the user can relatively easily time a press of the button or operation of the knob. As the timing is relevant for setting the aim, the use of a button or knob thereby may contribute to increasing the accuracy achievable using the weapon mount. In yet another embodiment of the weapon mount, the weapon mount further comprises a connecting element for connecting the base to the gun carriage whilst allowing rotation of the base around a second axis with respect to the gun carriage, the second axis being perpendicular to the first axis, so as to allow traversing the gun in the mounted position. Said traversing motion is also referred to as sweeping.

[0071] The second axis may be substantially vertical. In particular, the vertical axis may be vertical when the weapon mount is upright.

[0072] Allowing traversal / sweep of the base thus allows a user to sweep a gun in the mounted position, without changing the positon of the gun with respect to the weapon mount. Accordingly, the user need not release grip of the gun and / or the handle in order to sweep the gun.

[0073] The connecting element may comprise a pin of a pin-joint, the pin extending from the base. Accordingly, the gun carriage may comprise a guide of said pin-joint. The pin may, at least in use and / or when the weapon mount is upright, be arranged substantially vertically. Alternatively, the pin may extend, for instance upwards, from the gun carriage when the guide is provided at or in the base of the weapon mount.

[0074] In yet another embodiment, the mounting means are configured to releasably hold the gun. Accordingly, a user may decide to use the weapon mount or to shoot without support by the weapon mount by removing the gun therefrom.

[0075] In yet another embodiment of the weapon mount, the weapon mount further comprises a container for ammunition, the container being fixed to the mounting means.

[0076] By fixing the container to the mounting means, the container moves with respect to the base together with the mounting means and thus together with a gun in the mounted position. As such, ammunition in the container may be available for the gun irrespective of the positon of the mounting means and the gun with respect to the base.

[0077] In yet another embodiment of the weapon mount, the weapon mount is battery powered. A battery powered weapon mount is especially useful on moveable gun carriages, since the batteries remove the need for cabling or sliding contacts. In yet another embodiment of the weapon mount, the sensor comprises at least one gyroscope. A gyroscope may be particularly useful to sense an orientation and or rotation of the base with respect to an external reference.

[0078] The sensor may alternatively or additionally include an accelerometer and / or a magnetometer. The sensor may include multiple gyroscopes. The sensor may be arranged for fusing data from several sources, e.g. the sensor may be arranged for fusing gyroscope data with accelerometer and magnetometer data. In particular, the sensor may comprise an attitude heading reference system (AHRS)

[0079] By fusing accelerometer and / or magnetometer data, drift of the at least one gyroscope may be compensated for.

[0080] As an alternative, the sensor may be an IMU comprising at least one gyroscope with a relatively high bias stability.

[0081] In yet another embodiment of the weapon mount, the weapon mount further comprises at least one stop for limiting rotation of the mounting means with respect to the base around the first and / or the second axis in either one or both directions. The at least one stop may aid in limiting the direction of fire to a predetermined range. The at least one stop may be mechanical.

[0082] The invention also relates to a vehicle, vessel or aircraft comprising a gun carriage having mounted thereon a weapon mount according to any one or more of the preceding claims.

[0083] Such a vehicle, vessel or aircraft may have all of the above described features, alone or in any desired and suitable combination, and may present the corresponding advantages.

[0084] The gun carriage may be mounted movably with respect to the vehicle or vessel via for example a guide. A moveable gun carriage may allow shooting from different position on the vehicle, vessel or aircraft.

[0085] The weapon mount may be freely rotatable around the second axis with respect to the gun carriage, for instance via the above-described pin-joint.

[0086] Said free rotation may be defined as without interference of any actuator. As such, said free rotation may be effected by a user. The invention will be further elucidated with reference to the attached drawings, in which: Figures 1A and IB schematically show a side view of a vessel with a weapon mount according to the prior art;

[0087] Figures 2 and 3 schematically show a perspective views of a weapon mount according to one embodiment, with and without a gun and gun carriage respectively;

[0088] Figures 4A - 4C schematically show side views of the weapon mount of figures 2 and 3 in different elevations, with a gun in the mounted position and the weapon mount on a gun carriage;

[0089] Figure 5 shows more schematic representation of the weapon mount of figures 2 - 4C; Figure 6 shows a flow chart depicting operation of said weapon mount; and Figures 7A - 8B show schematically results of shooting tests.

[0090] Throughout the figures, like elements are referred to using like reference numerals.

[0091] Figures 1A and IB show a vessel 1 in the water 2. On the vessel 1 a weapon is mounted on a conventional weapon mount 4. A soldier 5 is shown using the weapon 3 to aim at a target 6. Under ideal conditions, a soldier 5 would be able to hit target 6 with reasonable accuracy, as shown by bullet trajectory 8 in figure 1A.

[0092] Conditions are however not always ideal. As an example, a wave 7 is shown in figure IB, the wave 7 tilting the vessel 1. As a result, the weapon 3 is also tilted along with the mount 4 and the soldier 5, causing a substantial miss of the target 6 as shown by trajectory 8.

[0093] As a result, the threat the weapon 3 imposes on an enemy is reduced significantly under non-ideal conditions, as the enemy knows it would be difficult for the soldier 5 to hit the target 6.

[0094] Figures 2 - 4C show a weapon mount 9 according to the invention. The weapon mount 9 includes a base 10 which can be fixed to a gun carriage 11. The gun carriage 11 is arranged on a vehicle, vessel or aircraft (not shown). The weapon mount 9 further includes mounting means 12. The mounting means 12 are configured to hold a gun 13 (dashed lines in figure 2) in a mounted position. The mounting means 12 in the shown weapon mount 9 have a set of hooks 14 and a latch 15 for holding the gun 13. Of course, other mounting means may be used alternatively. By removing latch 15, the gun 13 can be taken out of hooks 14 to remove it from the mounting means 12, and vice versa. The mounting means 12 are connected to the base 10 via pivot mechanism 16.

[0095] The pivot mechanism 16 allows a pivoting motion of the mounting means 12 with respect to the base 10 around a first axis 17. In the illustrated embodiment, the pivot mechanism 16 is limited by means of a mechanical stop comprised of a slotted plate 37 fixed to the base 10 and a stopping pin 38 guided in a slot of the slotted plate 37 and fixed to the mounting means 12.

[0096] In use, the first axis 17 is substantially horizontal and substantially perpendicular to a view axis 18 of the gun. The view axis of the gun 18 may also be referred to as direction of fire 18. Therefore, a rotation of the mounting means 12 around the first axis 17 changes the elevation E of the gun. As shown in figures 4B and 4C, the elevation E is defined as an angle of the gun 13 with respect to the horizon H. The weapon mount 9 further comprises an actuator 19 which is configured to pivot the mounting means 12 about the first axis 17 with respect to the base 10 accordance with a command signal. In this embodiment the actuator 19 is a linear actuator, which can retract and extend in correspondence with the command signal. The illustrated actuator 19 is connected to the mounting means 12 via a pin connection 29. Here, the actuator 19 is connected to the base 10 via a flexible connection 30 on a housing 20, which is fixedly connected to the base 10. The flexible connection

[0097] 30 allows a certain play in both rotation and translational directions other than a working direction of the actuator, to avoid overconstraining the actuator 19. The pin connection 29 comprises a pin

[0098] 31 and a guide 32 for guiding the pin 31, and also serves as a decoupling mechanism by allowing a user to remove the pin 31 from the guide 32. Upon removing the pin 31 from the guide 32, the actuator is decoupled from the mounting means 12, allowing a user to move the mounting means irrespective of the actuator 19. The guide 32 further forms the ball of a ball-and-socket joint, so as to allow rotation with respect to a socket fixedly connected to the mounting means 12, thereby allowing rotational movement to avoid overconstraining the actuator 19.

[0099] Inside the housing 20, a case 21 is arranged for housing a sensor comprising an attitude heading reference system including a gyroscope (not shown). The sensor is configured to sense an angular position with respect to the external world, and to provide a sensor signal in accordance therewith. The sensor senses the angular position around three mutually perpendicular axes. The weapon mount 9 further comprises control means, also arranged in the case 21 and not shown in the figures, connected to the sensor for receiving the sensor signal and to the actuator 19 to provide the command signal. The housing 20 is arranged in the same horizontal plane as the pivot mechanism 16, towards a side and towards a front of the weapon mount 9. As such, the gun 13 can be elevated freely without engaging the housing 20. Further, the housing 20 remains above a horizontal plane D defined by a bottom of the base 10, regardless of the elevation of the gun 13. A battery may be provided in the housing 20, for powering the weapon mount 9.

[0100] In the illustrated embodiment, the weapon mount 9 further includes a handle 22 including a grip part 23. The handle 22 is fixedly connected to the mounting means 12, so that the mounting means 12 may be moved by a user exerting force on the grip part 23 of the handle 22. The grip part 23 is arranged lateral of a grip 24 of the gun 13, about a shoulder-width away from said grip 24 of the gun 13. A user interface 25 is arranged on the handle 22 near the grip part 23, so as to be accessible to a user holding the grip part The user interface 25 may include a first button 26 and an up / down button 27 which also has a neutral position, and a reset button 28.

[0101] Using the first button 26, a user can switch between two operational modes of the weapon mount 9. In the first operational mode the actuator 19 is inactive, so that a user can rotate the mounting means 12 and thus the gun 13 with respect to the base 10. When inactive, the actuator 19 allows the mounting means 12 to rotate freely around the first axis 17 with respect to the base 10. In the illustrated embodiment, this is achieved by the actuator 19 providing a relatively small mechanical resistance to the pivoting motion, so that a user can pivot the mounting means 12 by using manual force. As an alternative, a force sensor could have been provided to sense manual force exerted by a user, which sensed force may then be used to control the actuator 19 to move in the direction corresponding to the exerted force.

[0102] In the second operational mode, the control means provide the command signal in dependence of the sensor signal so that the actuator 19 pivots the mounting means 12 around the first axis 17 with respect to the base 10 so as to compensate for a rotation of the base 10 around the first axis 17, thereby keeping the elevation E constant. Based on the sensor signal, the control means register a rotation of the base 10, and calculate, using goniometric calculations, a predicted change in elevation E of the gun 13 as a result of said rotation. The control means further provide the command signal to compensate for the predicted change in elevation E, the actuator 19 thereby keeping the elevation E constant. In order to keep the elevation E constant, the control means are configured to store an angular position of the base 10 based on the sensor signal upon switching to the second operational mode. The sensor signal is then compared to the stored angular position in order to provide the command signal for keeping the elevation E constant.

[0103] Using the up / down button 27, a user can increase or decrease the elevation E of the gun in the second operational mode. For this purpose, the control means are configured to change the command signal in order to change the elevation E of the mounting means 12 based on an adjustment signal triggered by the up / down button 27. The up / down button 27 is configured to provide a pulsed adjustment signal, so as to allow incremental change of the elevation E.

[0104] Using the reset button 28 the user may bring the gun to a predetermined elevation E. For this purpose, the control means are configured to change the command signal to move the mounting means 12 to a predetermined elevation E upon receiving a reset signal provided by the reset button 28.

[0105] The base 10 further includes connecting element 33, which in the shown embodiment comprises a pin 34 of a pin-joint. The pin 34 may be inserted into a corresponding guide (not shown) in a gun carriage 11 , in order to connect the base 10 to the gun carriage 11. The pin j oint allows rotation of the base 10, and thus of the gun 13 with respect to the gun carriage 11 around a second axis 35, which is perpendicular to the first axis 17. As such, a user can traverse or sweep the gun 13. Said traversing motion is mechanically limited by a stop 39 fixed to the base 10 (see figure 2) and guided in a slot 40 of the gun carriage 11.

[0106] Finally, the weapon mount comprises a container 36 configured for holding ammunition. The container 36 is fixed to the mounting means 12, and thus moves in accordance therewith.

[0107] Figure 5 discloses the weapon mount 9 having a base 10 and mounting means 12. The mounting means 12 are pivotable with respect to the base 10 via the pivot mechanism 16. The pivot mechanism 16 allows pivoting around the first axis 17, shown running normal to the plane of figure 5. The mounting means 12 are configured to mount a gun 13 thereto. As the gun 13 is not part of the weapon mount 9, the gun 13 is shown in dashed lines. A connecting element 33 is connected to the base 10 so that the base 10 can be connected to e.g. a gun carriage 11. Also shown is a second axis 35, which in figure 5 is vertical, about which the weapon mount 9 can be rotated to traverse or sweep the gun 13. The connecting element 33 may facilitate said rotation about the second axis 35. The weapon mount 9 further includes an actuator 19, which is connected between the mounting means 12 and the base 10, in order to drive a pivoting motion of the mounting means 12 with respect to the base 10 around the first axis 17 as allowed by the pivot mechanism 16. A sensor 40 is provided to sense an orientation of the base 10. A sensor signal 41 corresponding to the orientation is passed to control means 42, which in turn control the actuator 19 with a command signal 43.

[0108] The weapon mount 9 may function as shown in figure 6. Figure 6 shows in dashed-dotted lines a first operational mode 51 and a second operational mode 52 of the weapon mount 9. In the first operational mode 51, the actuator 19 is inactive as depicted by a single step SI. During this step SI, i.e. when the actuator 19 is inactive, the actuator 19 allows the mounting means 12 to rotate freely around the first axis 17 with respect to the base 10, for instance by providing a relatively small mechanical resistance to the pivoting motion, so that a user can pivot the mounting means 12 by using manual force. In the second operational mode 52, an orientation of the base 10 is sensed by the sensor 40 as depicted by second step S2. Then, in a third step S3 a predicted change in elevation E of the gun 13 as a result of a change in orientation of the base 10 is calculated, but could alternatively be looked up in e.g. a table. Further, in a fourth step S4 the actuator is controlled to pivot the mounting means 12 with respect to the base 10 in order to keep the elevation E of the gun 13 substantially constant. As shown by the arrows within operational mode 52, this process is repeated as long as the second operational mode 52 is active.

[0109] A press of the first button 26 is shown as first button operation 26’. As visualized by arrows 53, 54, the operation 26’ of the first button 26 causes the weapon mount 9 to switch between the first 51 and second 52 operational mode.

[0110] A press of the up / down button 27 is shown as up / down button operation 27’. As visualized by arrow 55, the operation 27’ of the up / down button 27 causes the control means 42 to increase or decrease the elevation E of the gun 13 in a step S5, which in the shown flow chart introduces additional input to the calculation step S3. Of course the step S5 could alternatively lead to steps S2 or S4 if desired, if the elevation E can be suitably changed accordingly.

[0111] A press of the reset button 28 is shown as reset button operation 28’. As visualized by arrow 56, the operation 28’ of the reset button 28 causes the control means 42, in a step S6, to control the actuator 19 to move the mounting means 12 to a predefined elevation. In the shown flow chart this is achieved by providing additional input to the calculation step S3, but said step S6 could alternatively lead to steps S2 or S4 if desired, if the predefined elevation can suitably be achieved.

[0112] Although button operation 26’, 27’ and 28’ are shown outside of the operational modes 51, 52, the buttons 26, 27, 28 may be operated in any mode. In particular, the first button 26 may be operated in one operational mode in order to switch to another. The up / down button 27 may be operated in the first operational mode 51 to switch to the second operational mode 52 and to increase or decrease the elevation E, and / or may be operated in the second operational mode 52 in order to increase or decrease the elevation E. The reset button 28 may be operated in any operational mode 51, 52 to move the mounting means 12 to the predefined elevation, and may if desired switch to the first 51 or second 52 operational mode respectively. Alternatively, if operated in the first operational mode 51, the reset button 28 may activate the first operational mode 51 again after the predefined elevation has been achieved. TESTs

[0113] Two tests were performed using the weapon mount as described herein, having mounted thereon a weapon. The weapon mount was set up on a platform that could be moved in multiple directions as desired. A qualified soldier was asked to fire rounds during 10 second tests at a target in a shooting range.

[0114] Using a weapon mounted camera, the aim of the weapon during the tests was recorded. For each test, the aim is shown in a plane having indicated thereon the target and the outline of the tunnel forming the shooting range (see figures 7A - 8B). Shots were made in three round bursts, approximately 2 bursts were made during each test

[0115] During the first two tests, the platform was rotated about the transversal axis so that the elevation of the weapon mounted on the weapon mount would change, according to a sinusoidal excitation. The rotation also caused a translational movement in the height direction of the platform. During the first test (figure 7A) the weapon mount was inactive. During the second test (figure 7B) the weapon mount was active.

[0116] Figures 8A and 8B show results of similar tests, in which a multi-dimensional motion profile was imposed on the platform. The platform was excited in all six degrees of freedom. The motion profile corresponds to motion a ship is likely to encounter in high seas. In these tests, blanks were fired instead of bullets, due to the soldier’s safety concerns caused by inaccuracies when the weapon mount was inactive (figure 8A). Figure 8B shows the results with the weapon mount active.

[0117] RESULTS

[0118] Figures 7A - 8B show a target 99, the tunnel of the shooting range 98 and the aim of the weapon 79 during the test.

[0119] As can be seen clearly in figure 7A, the movement of the platform induces inaccuracies in the soldiers aim. One indicator for difficulty aiming is the fact that large offshoots exist. These offshoots correspond to perturbations caused by movement of the platform combined with the soldiers attempt to compensate. As a result, the offshoots may also be overshoots of compensation. In figure 7B, the weapon mount was activated. Accordingly, the soldier need no longer compensate in the elevation direction. Since the spread in the vertical direction is in the same order of magnitude as in the horizontal direction, the weapon mount is considered effective. The spread can be viewed as the distance between leftmost and rightmost aims or the uppermost and lowermost aim during the test. Another indicator for difficulty aiming is the speed at which the aim changes. In figure 7A, the total length of the line is much longer than in figure 7B, whilst the test was just as long. Therefore on average, the rate of change of the aim is slower. This not only allows more time on target (the total time during which the aim is sufficiently close to the target), but also allows the soldier a bigger window to pull the trigger when the aim is on target.

[0120] In figure 8A a much larger spread can be seen in the horizontal direction as compared to figure 7A, because the platform was activated in multiple directions in figure 8A (and 8B) similar to how a boat may be moved by waves.

[0121] Comparison with figure 8B allows to conclude that not only did the vertical aim increase by activation of the weapon mount (the spread is lower, and the total length of the line is reduced), but the horizontal aim was also increased: the horizontal spread is reduced.

[0122] It can therefore be deduced the weapon mount is highly effective for its intended purpose of allowing shoot form e.g. a vessel or vehicle.

[0123] This was corroborated by the soldier, who explained that in the test for figure 8A he considered it unsafe to shoot anything other than blanks, whereas when the weapon mount was active he considered shooting projectiles (but did not for the sake of the test).

[0124] Although the invention has been described hereabove with reference to a number of specific examples and embodiments, the invention is not limited thereto. Instead, the invention also covers the subject matter defined by the claims, which now follow.

Claims

Claims1. Weapon mount for use on a vehicle, vessel or aircraft, the weapon mount comprising:- a traversing base which can be rotatably fixed to a gun carriage on the vehicle, vessel or aircraft so as to allow traversing of the base;- mounting means connected to the base, wherein the mounting means are configured to hold a gun in a mounted position, the mounting means having an elevation corresponding to an elevation of the gun in the mounted position;- a pivot mechanism placed between the base and the mounting means, the pivot mechanism allowing a pivoting motion about a first axis of the mounting means with respect to the base, so that the elevation of the mounting means can be changed; and- an actuator configured to pivot the mounting means about the first axis with respect to the base in accordance with a command signal, characterized by- a sensor configured to sense an angular position or rotation of the base with respect to an external reference, and to provide a sensor signal in accordance with the sensed angular position or rotation respectively;- control means, connected to the sensor for receiving the sensor signal and to the actuator to provide the command signal; and- a user interface connected to the control means for providing a switching signal, wherein the control means are configured to switch between a first and a second operational mode of the weapon mount based on the switching signal, wherein in the first operational mode the actuator is inactive, and in the second operational mode the control means provide the command signal in dependence of the sensor signal so that the actuator pivots the mounting means around the first axis with respect to the base so as to compensate for changes in the elevation of the mounting means caused by traversing the base when it is tilted.

2. Weapon mount according to the previous claim, wherein the sensor is further configured to sense an angular position and / or rotation of the base about the first axis and a second and a third axis, both being substantially perpendicular to each other and the first axis, and wherein the control means are configured to, in at least the second operational mode:- calculate or lookup a predicted change in elevation of the mounting means based on the sensed angular positions and / or rotations; and- provide the command signal to compensate for the predicted change in elevation of the mounting means, the actuator thereby keeping the elevation of the mounting means substantially constant.

3. Weapon mount according to any one or more of the preceding claims, wherein the control means are configured to store an angular position of the base based on the sensor signal upon switching to the second operational mode, and to provide the command signal in accordance with a comparison of the sensor signal and the stored angular position in the second operational mode.

4. Weapon mount according to any one or more of the preceding claims, wherein the actuator is a linear actuator which is rotatably connected to the mounting means in order to apply a torque on the mounting means around the first axis.

5. Weapon mount according to any one or more of the preceding claims, wherein the user interface is further configured to provide an adjustment signal to the control means upon receiving user input, wherein, in the second operational mode, the control means are configured to change the command signal in order to change the elevation of the mounting means based on the adjustment signal.

6. Weapon mount according to the previous claim, wherein the control means are configured to incrementally change the elevation of the mounting means on the basis of the adjustment signal.

7. Weapon mount according to any one or more of the preceding claims, wherein the user interface is further configured to provide a reset signal to the control means upon receiving user input, wherein the control means are configured to change the command signal to move the mounting means to a predetermined elevation upon receiving the reset signal.

8. Weapon mount according to any one or more of the preceding claims, further comprising a handle fixedly connected to the mounting means.

9. Weapon mount according to the previous claim, wherein a grip part of the handle is disposed at a distance from the mounting means.

10. Weapon mount according to the previous claim, wherein the mounting means have a view axis corresponding to a view axis of a gun in the mounted position, a grip of the gun defining a grip position along the view axis, wherein the grip part is arranged at a position along the view axis corresponding to the grip position along the view axis.

11. Weapon mount according to claim 9 or 10, wherein the mounting means have a vertical axis corresponding to a vertical axis of a gun in a mounted position in the mounting means, a grip of thegun defining a grip position along the vertical axis, wherein the grip part is arranged at a position along the vertical axis corresponding to the grip position along the vertical axis.

12. Weapon mount according to any one or more claims 9 - 11, wherein the user interface is arranged on the handle.

13. Weapon mount according to any one or more of the preceding claims, further comprising a decoupling mechanism for decoupling the actuator from the mounting means.

14. Weapon mount according to any one or more of the preceding claims, wherein at least the actuator, the sensor and the control means are arranged towards a side of the base and / or the pivot mechanism and / or the mounting means.

15. Weapon mount according to any one or more of the preceding claims, the base having a bottom defining a plane, which in use is substantially horizontal, wherein at least the mounting means, the actuator, the sensor and the control means are arranged above said plane, regardless of the elevation of the mounting means.

16. Weapon mount according to any one or more of the preceding claims, wherein the user interface comprises at least one button configured to trigger the switching signal.

17. Weapon mount according to any one or more of the preceding claims, wherein in the first operational mode, the actuator allows the mounting means to rotate freely around first axis with respect to the base.

18. Weapon mount according to any one or more of the preceding claims, further comprising a connecting element for rotatably fixing the base to the gun carriage whilst allowing rotation of the base around a second axis with respect to the gun carriage, the second axis being perpendicular to the first axis, so as to allow traversing the gun in the mounted position.

19. Weapon mount according to the previous claim, the connecting element comprising a pin of a pin-joint, the pin extending from the base.

20. Weapon mount according to any one or more of the preceding claims, wherein the mounting means are configured to releasably hold the gun.

21. Weapon mount according to any one or more of the preceding claims, further comprising a container for ammunition, the container being fixed to the mounting means.

22. Weapon mount according to any one or more of the preceding claims, the weapon mount being battery powered.

23. Weapon mount according to any one or more of the preceding claims, wherein the sensor comprises at least one gyroscope.

24. Weapon mount according to any one or more of the preceding claims, further comprising at least one stop for limiting rotation of the mounting means with respect to the base around the first and / or the second axis in either one or both directions.

25. Vehicle, vessel or aircraft comprising a gun carriage having mounted thereon a weapon mount according to any one or more of the preceding claims.

26. Vehicle, vessel or aircraft according to the previous claim, wherein the gun carriage is mounted movably with respect to the vehicle or vessel.

27. Vehicle, vessel or aircraft according to the previous claim, wherein the weapon mount is freely rotatable around the second axis with respect to the gun carriage.

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